public void NthElement_ShouldBe_SumOfTwoPreviousElements(int elementNumber)
{
// Arrange / Act
var fibonacciSequence = new FibonacciSequence(elementNumber);
// Assert
Assert.AreEqual(fibonacciSequence.Last(), fibonacciSequence.SkipLast(1).TakeLast(2).Sum());
}